Steam boiler



C. H. DAVY STEAM BOILER Aug. 15. 1933.

Filed March 17; 1950 Patented Aug. 15, 1933 T OFFICE STEAM BOILER Christopher Humphrey Davy, London, England,

assigner to The Babcock & Wilcox Company, Bayonne, N. J., a Corporation of New Jersey Application March 17,

1930, Serial N0. 436,275,

and in Great Britain October 14, 1929 14 Claims.'

This invention relates to boilersV and more particularly to sectional boilers which are made up of separate sections associated together so as to form a unitary construction, and anA object of this invention is to provide a boiler of this type constructed and arranged to enable a relatively high rate of evaporation per unit of heating surface.

This and other objects which will be apparent to those skilled in this particular art are accomplished by means of the invention `illustrated in the'accompanying drawing which is a diagrammatic sectional view through a steam generating boiler constructed in accordance with one embodiment of this invention.

The particular embodimentl of this invention which is illustrated in the accompanying drawing includes two boiler sections each of which includes separate banks of tubes and each of which is provided with the usual steam and water separating drum.V In the present invention an additional drum is provided which is connected to each of the separating drums and which is also connected to the uptake headers of each bank of tubes. Y

As illustrated, -the diiierent boiler sections are similar in construction and' each includes three banks oftubes 1, 2 and 3 of which the upper banks 2 and 3 are spaced from the lower bank l and an interdeck superheater 4 located in the space thus provided. Downtake headers 5 for the upper banks of tubes are connected to the water space of .the associated steam and water drum 6 in the usual way, and downtake headers 7 for the lower bank of tubes are nippled to the downtake headers 5. Steam and water circulators 8 connect the upper portion of the usual uptake headers 9 of the upper tube bank to the steam space of the drum 6, but the uptake header 10 of thelower bank is connected directly by connections 11 with a separate steam drum l2 which also has connections 13 connecting the steam drum with the upper portion ofthe uptake headers 9 above the point at which the circulators 8 communicate therewith. Pipes 14 connect the upper portion of the steam drum with the steam space of each separating drum and similar pipes 15 connect the lower portion of the steam drum with each of the separating drums. Y

A brickwork arch 16 is located between the two boiler sections beneath the lower uptake headers and this arch is-water cooled by means of pipes 17 which extend between the lower part of the downtake headers of the lower banks vof each unit across the surface of the arch 16 to the uptake headers of the lower banks of the other boiler unit, thus cooling the arch 16 and providing connections between the water spaces of the separate boiler units. As illutrated, the superheater headers 17 are located out of the path of the flue gases and in such a position that the tubes leading from the boxes to the superheated tubes proper do not need to pass between nipples connecting the upper and lower banks of tubes.

The boiler can be suspended from the drums and tubes of the uptake headers while the lower banks are shown as supported at their uptake ends on a centrally disposed girder 18.

What I claim as new and desire to secure by Letters Patent is:

l. In a Water tube steam boiler installation,

- an inter-deck steam superheater including superheater headers, and water tube sections having boiler headers forming opposite walls embracing the superheater headers and interposed between the latter and oncoming furnace gases to protect the superheater headers.

2. Steam generating apparatus oi the classv described, comprising, in combination, a boiler setting providing a chamber for the passage of heating gases, av support extending across the chamber, confronting water tube boiler units presenting an upwardly Widening dead ZoneV above the support, a plurality of superposed Water tube boiler sections comprising each unit, uptake headers dening the dead zone, more remote downtake headers opposite the uptake headers and located at slightly lower levels, a steam drum located at a level above the highest boiler sections, risers Yconnected to the uptake headers of the opposed lowermost boiler sections and extending upwardly to the steam drum, the portions of said conduits immediately above the connected uptake headers being bent abruptly toward each other and toward the vertical center of the dead Zone, pairs of superheater headers located in the dead zone immediately above said bent portions, inter-deck -superheaters connected with said headers and located above the lower boiler sections of each unit, and means contacting with theboiler sec- -tion headers for substantially preventing the passage of heating gases into or through the dead zone.

3. A water tube steam boiler installation comprising, in combination, opposed boiler units arranged across a boiler setting, superposed water tube boiler sections of the Babcock & Wilcox iis type constituting each unit, confronting uptake headers for the sections, connected downtake headers opposite the uptake headers, said confronting headers preventing heating gas passage to an interposed dead Zone extending throughout substantially the entire vertical cxtent of the installation, a steam drum at a level above the topmost uptake headers, a separator drum for each unit, uptake conduits connecting the lowermost uptake headers with the steam drum to provide the lower sections with a partially independent circulation, steam conduits connecting the topmost uptakeY headers with the steam drum, circulator conduitsleading from the topmost uptakeheaders to the separator drums, and drum conduits communicating with the steam drum below its water line and leading to the separator drums.

4. Steam generating apparatus of the class described, comprising, in combination, a boiler setting providing a chamber for the passage of heating gases, a support extending across the chamber, a multiple tube bank water tube boiler extending across the passage and the support and consisting of confronting boiler units presenting an upwardly widening dead zone above the support, a plurality of superposed water tube boiler sections comprising each unit, uptake headersV dening the dead zone, downtake headers opposite the uptake headers and located at slightly lower levels, a steam drum located at a level above the highest boiler sections, means connected to the uptake headers of the opposed lowermost boiler sections and extending upwardly to the steam drum to prevent the circulation of the lowermost section from interfering with othercirculation, superheater headers located in the dead zone above the level of the tops of the lowermost section headers, interdeck superheaters connected with said headers and extending oppositely between the two lower boilersections ofeach unit, and means contacting with the boiler section headers for substantially preventing the passage of heating gases into or through the dead zone.v A

5. In a twin boiler construction, a furnace, opposite boiler sections having spaced and confronting uptake headers, superheaters for the boiler sections, superheater headers, and means for preventing furnace gases from moving in the space between the confronting uptake headers, each superheater having a header located between opposite boiler sections and vin said space.

6. A water tube steam boiler installation comprising, in combination, a boiler setting, opposed banks Yof water tubes inclined upwardly toward positions at the middle of the boilersetting and meeting near the base of the installation, upwardly diverging uptake headers for said tubes located centrally of the setting, refractory means interposed between the lower ends of the lowermost uptake headers and oncoming furnace gases and cooperating with the headers to provide a central dead zone extending vertically throughout the greater part of the vertical extent of the tube banks, downtake headers opposite the uptake headers, a steam drum extending to a level above the tops of the uptake headers, steam conduits leading from the tops of said uptake headers Vto the steam drum, separating drums, circulators communicating with the uptake headers below said conduits and discharging into the separating drums, and connec- Vto the lower ends of the'lowermost uptake headnected downtake headers opposite the uptake rows of steam generating tubes adapted kto serve the tube banks and located centrally of the setting, arefractory protector interposed relative ers and oncoming furnace gases and cooperating with the headers to provide a central dead zone extending vertically throughout the greater part of the vertical extent of the tube banks, conheadersa steam drum extending to a level above the tops of the uptake headers, steam conduits leading from the uptake headers to the steam drum, separating drums, and water circulators communicating with the uptake headers below said conduits and discharging into the separating drums. Y

8. AIn uid heat exchange apparatus, banks of tubes conducting a fluid across a gas/pasa,v headers connected to the tubes, and a heat re- 100 sisting wall interposed relative to the lower ends of the headers and oncoming furnace gases and extending around the lower ends of the headers, said wall being supported by some ofl said tubesr which have portions reversely bent to pass '105 around the lower ends of theV headers and terminate in connections thereto at the side of the headers at positions above the bottom of the headers. i

9; In a water tube steam boiler, a boiler set- T10 ting, a pair of boiler units arranged across the .boiler setting, superposed water tube boiler sections constituting each unit, superposed uptake headers for the sections of each unit, a heatf, resisting arch extending across and beyond the '115 lower ends of the opposed lowermost uptake headers to receive them in a pocket and to protect them from excessive heating, tubes leading from the side of the lowermost uptake header,y f. of the first unit toward the uptake header of 1'20 that unit and then reversely across the arch to the lowermost downtake header of the second unit, and oppositely positioned tubes similarly leading from the lowermost uptake header of@ the second unit. n 125 10. In a boiler of the class described, banks of steam generating tubes, a row of inside headers foreach bank of tubes in the path of hot gases of combustion from the boiler furnace,^30

as slag screens for said first named tubes, the ends of said slag screen tubes extending beyond said headers and being bent back and expanded in said headers at the lower end thereof, refrac 'tory material secured to said slag screen tubes 135 at their bent portions, said tubes and refractory material serving as a protection to the bottom ofsaid'headers from the hot gases of combusexpanded into the lower end of said construction at its side, and a downtake header construc-l tion connected to the ends of the rst tubes op posite the uptake header, said additional tubes serving as a protection to the bottom of said uptake header construction from the hot gases of combustion.

12. In fluid heat exchange apparatus, a bank of tubes conducting a fluid across a gas pass, uptake headers connected into the fluid circulation of the apparatus, and a heat resisting wall interposed relative to the ends of the headers and oncoming furnace gases and extending around the ends of the headers, said Wall being supported by some of said tubes which pass around the lower end of the header and terminate in a connection thereto at the sides of the headers.

13. In fluid heat exchange apparatus, a furnace, a bank of vapor generating tubes,`an uptake header construction connected into the fluid circulation of the apparatus and disposed above the furnace, a row of additional steam generating tubes disposed between the header construction and oncoming furnace gases and connected into the fluid circulation of the apparatus, the ends of said additional tubes extending beyond said header construction and 'being bent back and expanded into the lower end of said construction at its side, and a down- `take header construction connected to the ends of the first tubes opposite the uptake header, .said tubes serving as a protection to the bottom of said header construction from the hot gases of combustion.

14. In a steam boiler organization; a furnace; opposed banks of horizontally inclined steam generating tubes; spaced uptake headers for said banks of tubes arranged at positions in the path of the furnace gases; downtake headers for the banks of tubes; and means interposed relative to the uptake headers and oncoming furnace gases for protecting the lower ends of the uptake headers against overheating; said means comprising refractory material and screen tubes connected into the boiler circulation and leading from positions below the downtake headers, the screen tubes having at their discharge ends reversely bent portions connected to an uptake header, the screen tubes supporting the refractory material.

CHRISTOPHER HUMPHREY DAVY` 

